Biosphere- Biogeochemistry Flashcards Preview

GEO1213: Our Changing Planet > Biosphere- Biogeochemistry > Flashcards

Flashcards in Biosphere- Biogeochemistry Deck (9)
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1
Q

What is silicate weathering

A

The slow weathering of the earths crust

2
Q

There is a large imbalance between oxygen and carbon in the atmosphere, more oxygen than carbon, why is this?

A

This is due to carbon being buried in the sea bed/lithosphere and not in the atmosphere

3
Q

We are now extracting and burning fossil fuels which is increasing long term carbon release by how much

A

100X

4
Q

How did burial of organic matter allow oxygen in the atmosphere and therefore life to form

A

Without burial, decomposition would have released almost all carbon as CO2 and consumed all the oxygen in the atmosphere so oxygen levels wouldn’t have built up to make complex life possible

5
Q

What percentage of the atmosphere does nitrogen make up?

A

78%

6
Q

Key biological processes in the nitrogen cycle

A

Nitrogen fixation
Mineralisation
Nitrification
Denitrification (output)

7
Q

How are humans having a major impact on the nitrogen cycle

A

Fertilisers

8
Q

Is there a +ve or -ve relationship between nitrogen deposition and plant growth

A

+ve (nitrogen fertilisation)

9
Q

What happens to gas solubility as temperature increases and what are the implications of this

A

It decreases, meaning oceans can take up less CO2 from the atmosphere (marine sink slowing down)